480 R. T, YOUNG 



to the ground and then walked to the backgrounds, somewhat nearer 

 the grass, but took the insect from the sand. 



Experiment 5. Figures 25 and 58. One Oecanthus quadripunctatus 

 was placed on grass and one on moist earth. The grackle at once 

 dropped to the ground, approached the grass first and took the insect 

 therefrom. The contrast here was greater in the insect-earth than 

 in the insect-grass combination. 



Experiment 6. Same as Experiment 4. In one minute the grackle 

 flew across the cage to a point nearer the grass than the sand, but walked 

 past the former to take the insect from the latter background, although 

 it was smaller than that on the former. 



Experiment 7. Figures 35 and 58. One Oecanthus was placed on 

 grass and one on sand, the latter combination presenting the greater 

 contrast. The grackle flew at once to a point nearer the grass back- 

 ground from which the prey was taken. 



Experiment 8. Same as Experiment 4. The grackle at once dropped 

 to the ground and in two minutes pasi^ed the grass to take the insect 

 on the sand background. 



Experiment 9. Same as Experiment 7. The contrast here was only 

 slightly greater between the insect and the sand than between the 

 former and the grass. The grackle almost immediately dropped to 

 the ground, passed the grass and then turned back and took the 

 insect from it. It then picked some crumbs from the sand. Evi- 

 dently the insects were not seen by the bird before it reached the 

 backgrounds. 



Experiment 10. Same as Experiment 5. After twenty minutes 

 the grackle approached the grass from which it took the insect, then 

 taking that on the earth. 



Experiment 11. Figures 25 and 37 . Three Melanoplus were placed 

 on hay mixed with moist earth, and three on sand. The latter com- 

 bination showed the greater contrast. The grackle passed first to 

 the hay from which it took the insects and then to the sand from which 

 they were next taken. 



Experiment 12. Figures 25 and 58. Four Oecanthus were placed 

 on moist earth and four on grass, the arrangement being as shown in 

 the accompanying diagram (fig. B). The grackle's line of approach 

 and the order of seizure of the insects are also shown in the diagram. 

 The grackle approached the backgrounds and began feeding in one 

 minute after the start of the experiment. The contrast in this experi- 

 ment was greater between the insects and the earth than between the 

 former and the grass. 



Experiment 13. Figures Jfi and 55. One Gryllus was placed on a 

 mixture of burnt paper and moist earth and one on ashes. For some 

 time (time not noted) the grackle remained on its perch. It then 

 fleAv to the ground and began picking up various small scraps of food, 

 finally approaching the backgrounds, but stopping to peck at some- 

 thing when but a few centimeters distant. It then took the cricket 

 from ;he earth and next that from the ashes. The contrast between 



